Usually , the next step up from bacteria in most food chains are protozoans ( such as amoebae and even microscopic crustaceans ) , and they are the biggest eaters of bacteria 通常，在大多数食物链中，细菌的上一层是原生动物（例如变形虫甚至微型甲壳类） ，它们也是细菌的最大食客。
Usually , the next step up from bacteria in most food chains are protozoans ( such as amoebae and even microscopic crustaceans ) , and they are the biggest eaters of bacteria 通常，在大多数食物链里，细菌的上一层便是原生动物（如变形虫乃至极微小的甲壳类） ，亦是细菌最大的食用者。
Under conditions of food shortage or other stresses , they come together to form a slug - like aggregation of maebas called a pseudoplasmodium , which acts like an individual organism 在食物短缺或其他压力胁迫的条件下，可以形成变形虫的集合体，叫做伪原生质团，成为一种独立的生物体。
Usually , the next step up from bacteria in most food chains are protozoans ( such as amoebae and even microscopic crustaceans ) , and they are the biggest eaters of bacteria 通常，在大多数食物链里，细菌的上一层便是原生动物（如变形虫乃至用显微镜才能看见的甲壳虫） ，而它们就是细菌的最大食用者。
Thirty - five genuses of periphytic algae were observed , which seneara , stauroneis and mougeotia were dominant populations . sixty species of protozoan were observed , which amoeba proteus , actinophrys so , litonotus fasciola were dominant populations . 2 优势种群为针杆藻属、辐节藻属、转板藻属；周丛原生动物60种，优势种群为大变形虫、放射太阳虫、砂壳虫、片状漫游虫。
